Senju Metal Industry Co., Ltd.

Hiroaki Kawamata

Keisuke Shinozaki

Kazuya Kitazawa

Shinji Kikuchi

Yuki Fujino

Hiroyoshi Kawasaki

Ryuji Ukai

Masato Shiratori

Sakie Okada

Ko Inaba

Kazuhiro Minegishi

Kengo Ohta

Syuta Akatsuka

Hayato Kaise

Takafumi Ohtake

This flux contains a first solvent and a thixotropic agent. The first solvent either has a viscosity of 10 Pa·s or more at 30° C. or is a solid at 30° C., has a boiling point of 200° C. or more, and has a weight loss rate of less than 96 mass % when heated to 230° C. The thixotropic agent contains a polyamide that is one or more substances selected from the group consisting of condensates of an aliphatic carboxylic acid and an amine and condensates of an aliphatic carboxylic acid, a hydroxy group-containing aliphatic carboxylic acid, and an amine. The content of the first solvent is 30 mass % or more with respect to the total mass of flux. The content of the polyamide exceeds 2 mass % with respect to the total mass of flux.

Flux, solder paste, and method for producing bonded body

A flux for a solder paste includes rosin, an activator and a solvent. The solvent includes a monoalkylene glycol-based solvent and a solid solvent that is solid at 20° C. The total content of the monoalkylene glycol-based solvent and the solid solvent ranges from 40% by mass to 60% by mass with the total amount of the flux as 100%. The content of the solid solvent ranges from 5% by mass to 25% by mass with the total amount of the flux as 100%.

Flux and solder paste

A flux for soldering contains 10 to 40 wt % of coumarin, 5 to 30 wt % of a monoamide-based thixotropic agent and 40 to 80 wt % of a solvent. A solder paste contains the flux and a solder powder. A method for producing a soldered product includes supplying the solder paste to a soldering portion of an electronic circuit board, mounting an electronic component onto the soldering portion and heating the soldering portion up to a temperature at which the solder powder melts in a reducing atmosphere containing a reducing gas to join the electronic component and the electronic circuit board.

Flux, solder paste and method for producing soldered product

Provided is flux containing rosin-based resin, a solvent, a thixotropic agent and an activator. The thixotropic agent includes any or both of hardened castor oil and bisamide-based thixotropic agent. The contents of the hardened castor oil and the bisamide-based thixotropic agent are respectively within the range of 4 wt. % or more and 10 wt. % or less and the range of 1 wt. % or more and 5 wt. % or less based on the total weight of the flux. The contents of the thixotropic agent are within the range of 5 wt. % or more and 15 wt. % or less based on the total weight of the flux. The activator includes hydrohalide, a halogenated aliphatic compound and an imidazole compound. The contents of the halogen in the flux are within the range of 9000 ppm or more and 50000 ppm or less.

Flux and solder paste using the same

It is an object of the present invention to provide a flux containing flux components homogeneously dispersed without precipitation of aggregates in addition to having an appropriate balance between fluidity and shape retention property, and a solder paste. A flux comprising 0.5 to 3.5 mass % of a sorbitol-type thixotropic agent selected from the group consisting of dibenzylidene sorbitol, bis(4-methylbenzylidene)sorbitol and a combination thereof, and 2 to 350 mass ppm of a sorbitol-type additive selected from the group consisting of sorbitol, monobenzylidene sorbitol, mono(4-methylbenzylidene)sorbitol and a combination thereof, and a glycol ether-type solvent.

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Chiba, Japan

Hiroaki Kawamata